1. Independent and Dependent Clauses
An independent clause is a group of words that contains a subject and verb and expresses a complete thought. An independent clause is a sentence.
Jim studied in the cafeteria for his chemistry quiz.
A dependent clause is a group of words that contains a subject and verb but does not express a complete thought. A dependent clause cannot be a sentence. Often a dependent clause is marked by a dependent marker word.
When Jim studied in the cafeteria for his Chemistry quiz. (NOT a sentence!)

2. Dependent Marker Words
A dependent marker word is a word added to the beginning of an independent clause that makes it into a dependent clause.
Examples:
When Jim studied in the cafeteria for his chemistry quiz. (NOT a sentence!)
Some common dependent markers are: after, although, as, as if, because, before, even if, even though, if, in order to, since, though, unless, until, whatever, when, whenever, whether, and while

3. Connecting dependent and independent clauses
There are two types of words that can be used as connectors at the beginning of an independent clause:
Coordinating conjunctions
Independent marker words

4. Coordinating Conjunctions
Coordinating conjunctions are used as connecting words at the beginning of an independent clause.
They are: for, and, nor, but, or, yet, & so. (FANBOYS)
When the second independent clause in a sentence begins with a coordinating conjunction, a comma is needed before the coordinating conjunction:
Example:
Jim studied in the cafeteria for his chemistry quiz, but it was hard to concentrate because of the noise.

5. Independent Marker Word
Some common independent marker words are: also, consequently, furthermore, however, moreover, nevertheless, and therefore.
An independent marker word is a connecting word used at the beginning of an independent clause.
These words can always begin a sentence that can stand alone.
When the second independent clause in a sentence has an independent marker word, a semicolon is needed before the independent marker word.
Example: Jim studied in the cafeteria for his chemistry quiz; however, it was hard to concentrate because of the noise.

6. Proper Punctuation Here are some examples of ways to combine independent and dependent clauses properly.
IC. IC.
I went to the store. I didn't buy any bread.
IC; IC.
I went to the store; I didn't buy any bread.
IC,CC IC.
I went to the store, but I didn't buy any bread.
IC; IM, IC.
I went to the store; however, I didn't buy any bread.
DC, IC.
When I went to the store, I didn't buy any bread.
IC DC.
I didn't buy any bread when I went to the store.